[Homer (OP)]

Hello folks, new to NS forums. I just wanted to ask if anyone had ever heard of the idea that perhaps there used to be a 5th planet between Mars & Jupiter?
I was just watching the Tunguska explosion documentary & they had mentioned the meteor belt that resides in that area and it make something click.

Is it possible that there was a 5th planet that was somehow destroyed ages ago and in turn may have lead the the dissipation of the Martian atmosphere?

Considering Jupiter has such a large gravitational field it isn't hard for me to imagine that it could have pulled another large object into the path of the planet and wham-mo, we get a large asteroid belt and perhaps the shockwave from that blew the atmosphere off of Mars.

The other possibility is that I'm clueless and should have stayed in school...

Would love to hear any comments and would like to know if this theory has already been posed.

[Karen W.]

Welcome to the site. I am sure someone with some knowledge in this area will come along to help answer your Questions. Holler if you need anything else.Enjoy the site.

[ukmicky]

I believe the theory is that Jupiters massive influence would prevent a planet from forming in that region of the solar system.

The way i see it is if a planet did once reside their then why has one not reformed from the debris of the original like how the moon did after a planet sized object collided with the earth and the only answer i can come up with is Jupiter.

[DoctorBeaver]

It's possible that a planet did, indeed, exist there at one time. I believe it is generally thought among those with expert knowledge of this subject that the rocky, inner planets formed before the outer gas giants. If that is the case, then any planet in that area could have been pulled apart as a result of being caught in a gravitational tug-o'-war between the sun and newly-formed Jupiter.

I cannot shed any further light on this as it all happened when I was very young and I have no recollection of events. []

[Exodus]

And what about this large asteroid heading towards us TU24... apparently we're in for a near miss... ?

[Exodus]

On monday, around tea time i reckon.

[Kryptid]

If the asteroid belt was condensed to form a planet, it would be a very small planet. According to http://www.solstation.com/stars/asteroid.htm, such a planet may be less than 930 miles across. That's smaller than Pluto.